Cement floor finisher



@man 'n.603 vrnrsnmg Filed lay 3. `19:59

...U-.- n n v af j; i-V AMT?! Patented Apr. 30', 1940 e l y .i

artsen:

csnrsnlrrnooafrmsnanf applicaties May .3f-ma Ns. :11.521

'rms invention 'relates tdaf machine. for fari.-

`and the like.

ishing or surfacingcement floors.;pavements,

Vventin: An object of the invention `is to provide a ma'- chine whichvwill surface cement byV machine trowelling. The surfacing vof cementdoors, pave-j ments, and the like heretcfcre has been gen-'- erally donevily-hand whereinthe vvfinisher` surfaces the -cement by` manipulatingva' finishing trowel thereover. During suchvmanipulation the vnishingtrowel is slightly tilted inthe direction of its movement and asv itlpasses `over the cement, applies or 'forms thesrnooth finished surface.It has heretofore-been proposed to supplant this hand labor with amachine capable of applying orv frming this finished surface. However,machines heretofore devised have generally proven unsuccessful becauseof the inability to form the desired smooth surface. This is mainly duetothe fact that the machinedriven trowels in such machines are incapableof lbeing tilted with respect to thel surface of the cement or if givena tiltwith respect to such cement the degree of tilt of the trowelsvcannot 25. be varied while the machine is in operation.

During the finishing operation with the trowel there is a tendency forthe water content of the cement te work toward the surface. Thus, tcwardthe end of the flnishing'operation there is 30 usually more watercontent on the surface than at the` start of the finishing operation.This increase of water content in the cement as the finishingoperationprogresses requires that the tilt of the trowel relative to thesurface be slightly varied.

- It is an object of the present invention to provide a cement .floorflnisher'wherein there are a plurality of motor-driven trowels that arecaused to pass over the surface of the cement licor to produce thefinished surface, and wherein the trowels are tiltably mounted 'so thatthey may impart the dsired smooth surface to the cement.

'More specifically, an object of the invention is to provide a cementfloor finisher having tiltable trowels so designed and arranged that thetilting may be adjusted or varied easily and while the machine is inoperation. Thus, as the finishing operation proceeds' and the watercontent 50 in the cement works its way toward the surface, the trowelsmay be easily and quickly adjusted to accommodate themselves to thechanging condition orconsistency of the cement being-nnished.

.-With the foregoing and other objects in view, which will be mademanifest in the following detailed descriptionv and specificallyvpointed out .in the appended claims, referencel is had vte theaccompanying drawing for an' illustrativel embodiment of the'invention,wherein:

Figure i-l is a' top planfview of the-'preferred form er sement :doorfunnierenflamme the in- Fig. 211s a -view insideele'vation of the same`aud-may be considered as having been taken in s,

.thedirection of the arrows 2 upon Fig. 1; 3 is a sectional view takensubstantially upon the line 3-3. uponFlg. 1;

Fig. 4 is aview in front elevation of the cement v floor finisher; and YFig. 5 is al partial view in vertical section of the upper end of thehandle. Referring to the accompanying drawing wherein similar referencecharacters deslgnate'similar partsV throughout, the improved cementfloor finisher comprises a suitable gear case I0 on `which is mounted asuitable source of power such as anelectric motor I'I'supplied withelectric current through conductors I2. An electric switch I3 is mountedon the handle IA which is Lattached to the gear case and this switch ispreferably'located near the upper end of the handle for convenience inturning on or shutting off motor II.

vWithin the gear case I have shown a.worm I5 which is driven by ymeansof a belt I6 off the motor. The worm meshes with a worm wheel I1 on avertical shaft I8. The lower end of the shaft Il extends into a socketI9 which is pinned thereon as by pin 20. IOn the lower end of 'a socketthere is a circular plate 2I attached to the'socket as by a pin 22. Theplate 2I provides three equally spaced bearings 23.

In the above-described construction the shaft I8 and the socket I9together may be considered .as a vertical motor driven shaft driven bymotor II. While a worm wheel is preferably employed so as to secure aspeed reduction it will be appreciated that any other suitable 'type ofdriving' connection between motor II and the vertical shaft may besubstituted therefor if found desirable.

A ring 24 is arranged concentrically around' the plate 2i. This ring hasthree pins 25 thereon extending radially inward and which are equallyspaced from each other. -Three trowels 26 are equally spaced from eachother and are radially arranged between plate 2I and ring 2d. Onthebacks of these trowels there are attached outer bearings 21 whichreceive the pins 25 andv inner bearing pins 23 which extend intobearings 23.. Arms 29 are pinned on the inner ends 'of the pins 28.These arms act as cranks capable of turning or tilting the trowels 26about their radial axes. The upper ends of the arms are equipped withsmall adjusting screws A39 engageable with the under surface or face ofa thrustcollar 3| fitting around socket I9.

' A lever .32is pivotaly mounted as at 33 on the form a shifting yoke orfork. 'I'he ends of lever 32 may be equipped with rollers 34 bearing onthe upper surface or face of the thrust collar. The outer end of thelever 32 has a Vcable 35 attached thereto which is trained up throughthe hollow handle Il where the cable is connected to a nut 36. A screw3'I extends into the nutA through a slot 38 in the handle so that thenut is slidably keyed in the handle. A knob 33 carrying a threaded stem46 is mounted on the end of the handle Il with the threaded stem Ilthreaded into nut 36.

The operation and advantages of the iinproved cement finisher are asfollows. On closing switch I3 themotor Il is energized to drive thevertical rotary shaft. The 4vertical rotary shaft causes the carrierplate 2| to rotate and the trowels 26 are thus-rotated about thevertical shaft as a center.

36 and causes lever 32 to have its outer end lifted. This forces thethrust collar 3l downwardly and causes the arms 29 on the inner ends ofthe trowels to be simultaneously swung` downwardly. The trowels are thussimultaneously tilted. The troweisare held -in tilted or adjustedpositions as long as knob 39 remains in adjusted position. The tiltingaction vmay -take place at any time while the` machine is in iioor thatis to be finished the machine can of course be pushed or pulled by meansof the handle. I find, however, it can also bereadily moved' in asidewise manner byeither lifting slightly or pushing'downwardly on thehandle. Thus, if the trowels shown in rFig.1 are driven by the motorin aclockwise direction lifting on the lhandle I4 will be effective to causethe machine to work itself toward the left. Conversely, if the handle I4 is pressed downwardly slightly, the tendency is for the machine towork itself toward the right. In this manner by either pushing orpulling on the handle r slightly elevating it or depressing it themachine will cause itself to progress inthe direction desired across thecement floor that is being finished.

` From the above-described construction it will be appreciated that theimproved cement'nisher will successfully supplant hand finishing ofcement floors. The trowels of the machine can be tilted and adjusted atany time during the operation to produce the desired fioating andfinished surface. While 'the vvnumber of trowels shown is three and thisnumber is preferred, it will be understood that the number oftrowelsemployed may vary and where desiredv the number of trowels may be.either decreased or increased. As each arm 29 is equipped with its ownadjusting screw for engagement with the thrust collar 3| thetrowels maybe accurately scope of the invention as defined by the appended claims.

v'Iilting of the trowels isl accomplished by turning knob 39 which.retracts nut I claim: 1. A cementfloor finisher comprising a pluralityof trowels, means for rotating the' trowels over the trowels about theirlongitudinal axes" during rotation and `holding-them in their tiltedpositions. l

2. A cement fioor finisher comprising a pluralu ity of trowelarmeans forrotating the trowels, said trowels being tiltably mounted, and means foradjusting the tilt ofthe trowels during rotation and holdingthetrowelsin tilted positions.

3.'A cement fioor finisher comprising means providing a carrier, meansfor rotating the carrier about a verticall axis, trowels tiltablymounted upon the carrier, and. means for simultaneously varying the tiltof the trowels during rotation thereof by the carrier and holding thetrowels in tilted positions. 4. A cement fioor providing a carrier,means for rotating the carrier about a vertical ,axistrowels,tiltablymounted` upon .the carrier and radially arranged with respect to theaxis of rotation of the carrier, and

means for simultaneously varying the tilt of the trowels `duringrotation thereof by thecarrier,

6. A cement fioor finisher comprising a vertical y shaft, means forrotating said shaft, a plurality of trowels radially arranged withrespect to the shaft and adapted to be rotated thereby, each troweibeing tiltably mounted, a thrust collar on the shaft, armson'the trowelsactuated by the thrust collar, means for adjusting each arm with respectto the thrust collar, and means for varying the position of thethrustcollar on the shaft whereby the tilt of the trowels may be varied.

7. A cement floor finisher comprising a motordriven, vertical shaft, athrust collar thereon, va

finisher comprising means thesurface of thefloor, and means for tiltingplurality of trowels radially arranged with respect to the shaft adaptedto be rotated thereby, each trowel being tiltable about its radial axis,means operable by the thrust collar for simultaneously varying the tiltof all the trowels, and means for shifting the position of the thrustcollar relative to the shaft. l

8. A cement floor finisher comprising a `motordrlven, vertical shaft, aring arranged around the bottom of the shaft, a plurality of trowelsradially arranged between the shaft and the ring, and means mounting theinner ends of the trowels on the shaft and their outer ends on the ringswhereby the trowels may be rotated by the shaft.

9. A cement floor finisher comprising a motordriven, vertical shaft, aring arranged around the bottom of the shaft, a plurality of trowelsradially arranged betweenl the shaft and the ring, means tiltablymounting the inner` ends of the trowels upon the shaft and the outerends of the trowels on the ring, a thrust collar-on the shaft. means forshifting the thrust collar relative to the shaft, and means operable bythe shifting of the thrust cenar for simuuaneously tilting the trowelsabout their radial axes. f

MARVIN EDWIN u

